Tag Archives: arXiv

Update: All seems to be well at the arXiv site now. Still no word about what happened.

This morning I read a tweet from Daniel Lemire saying that some papers have gone missing from arXiv.org, the primary repository for preprints in physics and some areas of mathematics and computer science. I checked and it seemed that a lot of more recent papers were missing in several searches that I tried.

Just now, I heard from Martin Roetteler that arXiv.org is redirecting to a random mirror site, e.g. the Australian, Brazilian or Chinese mirror. At the time of writing, at least the mirror sites seem to be working correctly.

Speculation is that perhaps the arXiv has been hacked, but at the very least least they are having some pretty major problems with the main servers at Cornell. It comes as a big shock because the arXiv has always been one of the most stable sites that I use regularly and the physics community depends on it. I can’t remember anything like this having happened before.

Dave Bacon has started a very interesting new website called Scirate. It is a Digg-like site for the physics arXiv. You can read his post about the site here. It only works for quant-ph at the moment, but I’d urge all fellow quantum travellers to sign up and take part in the experiment.

As is traditional with physics blogs, it is time to indulge in a spot of shameless self-promotion of my own work. I have just posted a paper on quantum dynamics as an analog of conditional probability on the arXiv. This is about a generalization of the isomorphism between bipartite quantum states and completely positive maps, that is often used in quantum information. The main point is that it provides a good quantum analog of conditional probability, so it may be of interest to foundations-types who like to think of quantum theory as a generalization of classical probability theory.

The paper was completed in somewhat of a hurry, to get it out in time for the conference on Foundations of Probability and Physics in Vaxjo taking place this week, where I am due to give a talk on the subject. No doubt it still contains a few typos, so you can expect it to get updated in the next couple of weeks. Any comments would be appreciated.